Photoelectric system



y 3, 1934- H. c. RENTSCHLER 1,957,729

PHOTOELECTRIC SYSTEM Filed Aug. 1, 1930 INVENTOR /i C. PEA/75641571 ATTORNE Patented May 8, 1934 UNITED STATES PATENT OFFICE PHOTOELECTRIC SYSTEM Application August 1, 1930, Serial No. 472,313

'7 Claims.

This invention relates to photo electric systems and more particularly to photo electric systems wherein it is desired to have extreme sensitivity to predetermined variations in the intensity of radiations coupled with a trigger device energized as a result of such radiation variations for the purpose of energizing an auxiliary electric circuit, actuating mechanism, or setting of alarm systems and the like.

In copending application Serial No. 448,809 filed May 1, 1930, entitled Photo electric system, I have disclosed a photo electric system of eX treme sensitivity which is energized by a direct electric current. Such a system while of great utility has commercial limitations.

One of the objects of the present invention is to provide such an ultra sensitive photo electric system which is operable directly from an alternating current source.

Another object of this invention is to provide a photo electric system operable directly from an alternating current source which is responsive to definite desired illumination values.

Another object of this invention is to provide a system responsive to predetermined radiations for the automatic control of illumination.

Other objects and advantages will become apparent as the invention is more fully disclosed.

In accordance with the objects of the present invention I have devised a photo electric system operable by alternating electric current.

The specific photo electric system devised comprises a gaseous conduction device of the starting anode type having an input and an output circuit, means associated with the input circuit for energizing said device from an alternating current source, means in the output circuit energized by a current flow in said device to energize external mechanism, photo electric responsive means associated with said input circuit to energize and ole-energize said gaseous'conduction device in response to variations in light radiations applied thereto, and means associated with said output circuit for regulating said photo electric responsive means, all as will be more fully disclosed.

Before further disclosing the nature and scope of my invention reference should be made to the accompanying drawing wherein'is shown in schematic diagram the photo electric system of the present invention.

Referring to the drawing a gaseous conduction device '1 is shown having a cathode 2 of relatively large area, a starting anode 3 and a main anode 4, the starting anode 3 being relatively close spaced to said cathode 2 by means of starting tip 5 extending from the surface of the oath-- ode to within a relatively short distance from said starting anode 3. This arrangement of electrodes provides a device having a definite break down potential. By applying to the main anode an electric potential, sufiicient to sustain the discharge when once initiated between the starting anode 3 and cathode 2, a so-called trigger action device is obtained.

The energization of the gaseous conduction device is obtained directly from an alternating current source such as a 110 volt 60 cycle line. One side of the A. C. line is passed through a resistance 6 to the anode 3 and one side of a condenser 7, and the other side of the A. C. line to the opposite side of the condenser 7 and to the cathode 2. The full 110 volt source is placed directly across the cathode 2 and main anode 4 of the gaseous conduction device 1. Ordinarily this source is insufficient to initiate a discharge therebetween but is sufficient to sustain the discharge when once initiated between the starting anode 3 and cathode 2.

When a charge has accumulated in the condenser of an intensity sufficient to break down the resistance of the gaseous conduction device 1 between the cathode 2 and starting anode 3, a discharge is initiated which is sustained by reason of the constant potential applied between the main anode 4 and cathode "2.

The current flow through the gaseous conduction device energizes the relay 8 which operates to close a spring'contact member 9 thereby effecting energization of incandescent lamp 10. The incandescent lamp 10, is illustrative of one modification of the present invention and it is to be understood that any other device such as a burglar alarm, mechanism of all types, a battery of lamps, etc. may be equally'as easily operated in place of the single incandescent lamp shown, without departing essentially from the nature and scope of the present invention.

The input circuit comprises the suitable source of potential in series with the resistance 6, the gaseous conduction device 1 and the relay 8. More specifically, it comprises the starting anode 3 of the gaseous conduction device 1 connected to one side of said resistance 6 having its other side connected to one side of said source of potential, and the cathode 2 of the device is connected to one side of the relay 8 having its other side connected to the other side of saidsourceof potential. The condenser '7 is connected in electrical parallel with the starting anode 3 and the cathode 2 and has 0 its terminals connected to the terminals of said electrodes.

The output circuit comprises the suitable source of potential in series with the gaseous conduction 5 device 1 and the relay 8. More specifically it comprises the main anode 4 of the device 1 being connected to one side of said source of potential, the cathode 2 of said device connected to one side of the relay 8 and the other side of the relay 8 10 connected to the other side of said source of potential.

To provide means to automatically control the operation of the glow discharge device 1 and consequent energization of external mechanism, I

employ photo electric cells responsive to predetermined radiation values. In the schematic diagram shown, it is contemplated that the circuit be employed in the automatic energization and de-energizaticn of street or house lighting systerns, wherein when the natural light values fall' to a predetermined value it is desired to automatically turn on artificial illumination, and when the natural light values have returned to a predetermined value to automatically shut off the f1 artificial illumination.

I obtain this automatic control by means of a plurality of photo electric cells 11 and 12 which are electrically connected across the condenser 7 in such manner as to form a leakage path for the" condenser. As shown, the photoelectric cell 11 has its cathode connected to that side of the condenser 7 connected to the relay 8 and the cathode 2 of the device 1. The anode of said photoelectric cell 11 is connected to the other side of said condenser 3 connected to one side of the resistance 6 and the starting anode 3. The photoelectric cell 12 has its anode connected to the anode of said photoelectric cell 11. The cathode of the photoelectric cell 12 is connected to the terminal 13. Connected to one side of said source of potential is one terminal of the lamp 10 and the other terminal of said lamp 10 is connected to a single pole switch 9 located between the terminal 13 and the terminal of the source of potential other than that to which 45. the lamp 10 is permanently connected. The single pole switch 9 constitutes the armature of the relay 8 and upon predetermined energization thereof is adapted to establish contact with the terminal other than 13 connected to the source 50.. of potential and when the relay is rendered inoperative the switch 9 establishes contact with the terminal 13. This leakage path prevents an accumulation of an electric potential in the condenser and energization of the gaseous conduci tion device 1 thereby. As the electrical conductivity of the photo cell is directly dependent upon the intensity of the light falling thereon it is apparent that as the intensity of the radiations 7 fall, the amount of current by-passed there- 5 through also falls and eventually a point is reached where the condenser 7 begins to accumulate an electrical potential. When the potential has reached the necessary value a glow discharge .in the gaseous conduction device 1 is initiated. By properly adjusting the condenser 7, which may be variable and by properly selecting the type and number of photo cells the control means may be made sensitive within any desired range of 7 radiations.

To reverse the automatic control of the external mechanism illustrated as lamp 10, it is necessary to employ a single photo cell in order to avoid what is known in the art as the hunting effect whereby the deenergization of the circuit is of increases and ultimately the current of the 110 volt source of supply through the resistance to the condenser is by-passed by the cell. This automatically cuts off the flow of current through the gaseous conduction device 1, thereby de-energizing the relay 8 and spring contact member 9 returns to open position as shown in the drawing and the current flow in the external mechanism 10 ceases.

At the same time the remaining photo cells, out out of circuit at 13 upon energization of the external mechanism 10, are returned to the photo electric by-pass circuit and are now cooperating with photo electric cell 11 to discharge the condenser '7. The specific types of photo electric cell employed will depend in part upon the type of radiations applied thereto in the control of the photo electric system.

t is apparent from the above disclosure that there may be many variations and departures made in the specific embodiment herein disclose without departing essentially from the nature and scope of the present invention as is set forth in the following claims.

What is claimed is:

l. A photoelectric system comprising a gaseous conduction device having an input and an output circuit, means associated with said input circuit to energize said device, a plurality of radiation responsive means associated with said input circuit 115 and cooperating with said first mentioned means for controlling said first mentioned means for energizing and de-energizing said gaseous conduction device in response to variations in radiations applied thereto and means in said output circuit and energized by current flowing therein to cut out one but not all of said radiation responsive means.

2. A photoelectric system comprising a gaseous conduction device of the starting anode type having an input and an output circuit, means associated with said input circuit operable by alternating current to apply between the starting anode and the cathode of said device, an electric potential sufiicient to energize said gaseous conduction device, a plurality of radiation responsive means associated with said first mentioned means for controlling the first. mentioned means for energizing and de-energizing said input circuit and means in said output circuit and operable upon current flow therein for cutting out one of said radiation responsive means while allowing said other radiation responsive means to be directly associated with said first mentioned means.

3. A photoelectric system operable by alternating current comprising an alternating current source of supply, a gaseous conduction device of the starting anode type having a cathode and two anodes arranged with said source of supply to have an input and an output circuit, a condenser in electric parallel with the gaseous conduction device and being connected to an anode and the cathode thereof, a resistance in series with said condenser and having one end thereof connected to the main anode of said device, a plurality of 150 radiation responsive means, one of said means being connected across the condenser for controlling said condenser for energizing and deenergizing said gaseous conduction device, a relay in series with said gaseous conduction device, said relay being adapted to be energized by a current flow in said output circuit to cut-out one but not all of said radiation responsive means.

4. A photoelectric system operable by alternating current comprising an alternating current source of supply, a gaseous conduction device of the starting anode type having a cathode and two anodes arranged to have an input and an output circuit, a condenser having one terminal thereof connected to the cathode of said gaseous conduction device, a resistance having one end thereof connected to the other side of said condenser and its other side connected to one of said anodes, a plurality of radiation responsive means across the condenser for controlling said condenser for energizing and de-energizing said gaseous conduction device, a relay in the output circuit of said gaseous conduction device and energized by a current flow in said output circuit, to cut out one but not all of said radiation responsive means.

5. A photoelectric system comprising a gaseous conduction device of the starting anode type, an alternating current source of supply, an input and an output circuit, said source of supply being common to both of said circuits, means connected to said device for applying an electric potential thereto to initiate a discharge therein, a plurality of radiation responsive means associated with said first mentioned means for controlling said first mentioned means for the energizing and de-energizing of said gaseous conduction device means in said output circuit and responsive to current flow therein to cut out one but not all of said radiation responsive means.

6. A system comprising a gaseous conduction device of the starting anode type, an alternating current supply, an input and an output circuit, means associated with said input circuit for applying an electric potential to said gaseous conduction device for initiating a discharge therein, radiation responsive means comprising a plurality of photoelectric cells in shunt relation with said first mentioned means for controlling said first mentioned means for the energization and de-energization of said gaseous conduction device, means in said output circuit and responsive to a current flow therein for cutting out one but not all of said photoelectric cells.

7. A system comprising a gaseous conduction device of the starting anode type, an alternating current supply, means associated with said input circuit to apply an electric potential to said gaseous conduction device to initiate a discharge therein, means to apply an electric potential in said output circuit to sustain the initiated discharge in said gaseous conduction device, radiation responsive means comprising a plurality of photoelectric cells in shunt relation to said first mentioned means for controlling said first mentioned means for the energization and de-energization of said gaseous conduction device, means in said output circuit and responsive to current flow therein to cut out one but not all of said radiation responsive means.

HARVEY CLAYTON RENTSCHLER. 

